How do motor mounts work?

I suspect I may need to align my engine after I re-install my trans. It looks like the alignment is adjusted from the front mount. It looks like side-to-side adjustment is adjusted by loosening a clamp, circle A on the pic, and forcing the engine sideways, perhaps with a large pry-bar.

It looks like there is an upper and lower (not in view) slotted screw locked by a nut for up and down adjustment (circle B).

Large corrections may be made by selecting bolting holes in the bracket (circle C).

Have I got it right?

What do I do with the rear (trans) mount while all of this movement is taking place?

If you pulled the trans., and not the engine, why would you have to adjust the engine mounts? If you reference mark the trans mounts, or better yet just take out the four bolts that attach the trans to the mount, you won't have to adjust anything.

Thanks Tim. I now know about the Fram - it will come off. That ribbed hose does not have wire in it. The last hose (the one that came on the boat from the previous owner) did and the wire rusted, broke up, and damaged my raw water pump. And you are looking at the left side motor mount of my '68. I didn't even suspect the mount was adjustable until I read some posts on this forum.
...and I am still not 100% sure if is - it just looks like it is.
I have not yet begun any work on my '66. The '66 just sits and I just stare at it.